WO1979001138A1

WO1979001138A1 - Roof

Info

Publication number: WO1979001138A1
Application number: PCT/SE1979/000096
Authority: WO
Inventors: A Regner; B Palsson
Original assignee: Persson G; Palsson A
Priority date: 1978-05-29
Filing date: 1979-04-20
Publication date: 1979-12-27
Also published as: DK152855C; EP0015973A1; DK34380A; DK152855B; SE7806116L

Abstract

A roof comprising a supporting deck (14) having a heat insulation (21) and a roof finish (23). The supporting deck (14) comprises a prefabricated element and supports a self-supporting panel (18) by means of rigid metal sheet sections (16) forming spacers between the supporting element (14) and the panel (18). The space below the panel (18) is filled with a soft heat insulating material (21).

Description

ROO F

The invention relates to a roof, comprising a supporting deck with a heat insulation applied on the top thereof and having a roof finish.

Today one common embodiment of such a roof comprises a concrete slab prefabricated or moulded in situ, and a supporting heat insulation placed thereon, the density of which is of the order of 200 kg/m³. On the top of this heat insulation the roof finish is applied in a conventional way. The reason for using a supporting heat insulation is to allow stepping on the roof when the roof finish is being applied. However, it is an obvious disadvantage to be left to the use of a supporting heat insulation having a density of the order mentioned above, considering that this insulation is very expensive; at present this price is of the order of 75 Swedish kronor per m² for a thickness of the insulation of 200 mm said thickness being prescribed according to the building standards applied for buildings in southern Sweden.

According to the present invention there is now provided a way of avoiding this expensive insulation the possibility of stepping on the roof being maintained; glass or mineral wool having a density of the order of 17 kg/m³ and a price of the order of 15 Swedish kronor per m² can be used for an insulation of the thickness mentioned above. This is achieved by a roof of the kind referred to above having the characteristics according to claim 1.

It is true, that the laminated structure of the roof according to the invention involves the supplementary use of a self-supporting panel and spacers supporting said panel, but the costs for these additional elements are far from being as large as the costs per square metre involved when using a supporting insulation.

One embodiment of the roof according to the invention will be described below with reference to the accompanying drawings in which

FIG. 1 is a perspective view having portions broken away, of a roof according to the invention, FIG. 2 is an enlarged cross sectional view taken, along line II - II in FIG. 1, FIG. 3 is an enlarged cross sectional view taken along line III - III in FIG. 1, FIG. 4 is an enlarged cross sectional view taken along line IV - IV in FIG. 1, FIG. 5 is a perspective view of a spacer with jointing connectors,

FIG. 6a is an end view of the dismounted connector,

FIG. 6b is an end view of the mounted connector, and FIG. 7 discloses a second embodiment of a connector used for jointing the two parts of the spacer.

FIG. 1 discloses a building structure made of elements moulded in situ or prefabricated, which comprises columns 10 supporting roof beams 11. The building has an outer wall 12.

On top of the roof beams 11 a roof comprising a number of prefabricated roof slabs 13 is arranged the dimension of the slabs being e.g. 6 x 2.4 m, and each of said roof slabs comprises in the embodiment shown a supporting lower deck made of corrugated iron sheet 14 galvanized or varnished and having a thickness of 0,65 - 1 mm. However, the roof slabs also may be made of a prefabricated concrete slab or the like. The corrugated sheet has a trapezoid profile which is preferred because planar supporting surfaces are obtained at the top and bottom sides of the sheet, but it is possible to choose other profiles within the scope of the invention. The corrugated sheet 14 is covered on the top side thereof with a vapour barrier 15 made of plastics film, having a thickness e.g. of 0.15 mm, and on top of the vapour barrier rigid Z-sections 16 of 1 mm metal sheet preferably galvanized metal sheet, are arranged, said sections extending across the ridges of the corrugated sheet 14 and being suitably spaced in the longitudinal direction thereof. They are attached at one flange thereof to the corrugated sheet, e.g. by means of blind rivets 17, FIG. 2, and the height of the sections corresponds to the required thickness of the insulating layer of the roof slab, e.g. 200 - 280 mm. The upper flange of the Z-sections 16 supports a self-supporting panel 18 which should be of fire class I and may comprise e.g. a cement stabilized wood-wool board. This panel is attached to the upper flange of the Z-section by means of screws 19 extending through the panel and screwed into the upper flange of the Z- section a pressure distributing washer 20 being provided on the top side. Preferably the screws 19 are of the type which is self-drilling and self-tapping. In the space between the vapour barrier 15 and the panel 18 in which the Z-sections 16 form spacers, a heat insulating material 21 is arranged, which can be soft and can comprise glass or mineral wool having a density of the order of 17 kg/m³. The panel 18 shall allow stepping and the Z-sections 16 shall have a sufficient rigidity to maintain the necessary distance of insulation as the panel 18 is loaded when being stepped upon.

The adjacent longitudinal, edges of the slabs 13 are arranged as shown in FIG. 3. The corrugated sheets 14 terminate at a lower flange 14' projecting from the sheet, at which they can be connected by overlap to the beam 11 by means of steel nails 22 which are shot into the beam by means of a nail firing tool. Due to the fact that the Z-sections 16 and the panels 18 terminate at a distance inwardly of the edge of the corrugated sheets 14 a sufficient space is obtained between the panels to allow the insertion of the steel nails 22. The vapour barrier 15 of adjacent panels, a flap 15' of which projects from the edge, is then welded or glued at these flaps. The space between adjacent roof slabs above the vapour barrier is filled with insulating material 21' of the same type as the insulating material 21, which can easily be filled into the space between the roof slabs. The panel 18 ends at some distance inwardly of the ends of the Z- sections 16, e.g. 25 mm inwardly of these ends, whereby the Z-sections can form abutment surfaces for ribs or strips 18' of the same material as that of panels 18 said ribs being located above the space filled with the insulating material 21'. The ribs are attached by means of screws 19 and washers 20 in the same manner as that described above with reference to the attachment of the panels 18 to the Z-sections 16.

Also at the short sides the panel 18 terminates at a distance from the edge of the sheet 14 so that the sheet is available to be attached to the beam along the short side by firing steel nails 22 into the beam 11. The space between the panels 18 at adjacent roof slabs at the short sides thereof is filled with insulating material covered by a rib or strip 18' of the same type as the panels 18. This rib may be attached by glueing, because the Z-sections are not available at the short sides for attaching the ribs in the manner shown in FIG. 3. The edges of the panels and the ribs may possibly be flanged to facilitate the glueing operation .

The roof constructed in this way may be covered conventionally be using a roof base paste board 23 glued on top of the panels 18 and the ribs 18'. During this work the roof can be unobstructedly stepped on. A roof slab of the type described above can be provided with an opening 25 having a protruding rim, as shown in FIG. 1, this opening being arranged by conventional trimming of the Z-sections 16 and by providing a metal sheet covering 25 inside the opening surrounded by the rim. This metal sheet covering preferably forms a flange around the opening on the lower side of the corrugated sheet 14. The roof base paste board 23 is drawn up on the outside of the rim in a conventional way, and a domed skylight or a skylight of a conventional type can be arranged on the rim. The complete work in arranging such a roof opening for one reason or another thus can be performed in a factory when producing the roof slab. FIG. 1 discloses how a roof slab according to the invention can be prefabricated to form a gutter at the base of the roof. Thus, it is shown that the roof slab closest to the base has a portion 13' the thickness of which decreases from a maximum at a longitudinal edge of the slab, i.e. the edge closest to the crown of the wall 12, over a distance which can be e.g. 500 mm, to merge into the thickness of the regular slab. The maximum thickness of the slab can be achieved by enlarging the Z-sections or by forming these to correspond with the shape of the slab, the insulation 21 being increased to completely fill the space between the panel 18 and the corrugated sheet 14 as shown in the drawing. The angle between the sloping edge portion of the roof slab and the rest of the roof slab forms a gutter, and the slab can be prefabricated with a roof drain 26 an interior drain pipe 27 which is connected to the drain, extending to the wall 12 and downwardly along said wall. The pipe may be let into the wall.

On the roof base paste board 23 a conventional roof finish, such as whether-proof board, metal sheet, roofing tiles etc., can be arranged. At the crown of the wall the end finish ca be made in a conventional way by extending the roof base paste board and covering layers of paper, if any, upwards along the inside of the crown of the wall the crown then being covered with a metal sheet cap 28.

FIG. 1 also discloses another way of arranging the end finish. A board 29 is drawn up to the upper edge of the panels 18 and the vapour barrier 15 is drawn up above the edge of the roof slab and over the panel 18. A metal sheet cap 30 is arranged in a conventional way over the vapour barrier 15 and the board 29. The roof base paste board 23 is laid over the upper side of the metal sheet cap 30 and ends at the vertical portion thereof. The board 29 may, of course, include an inside insulation, and a corresponding brick wall may be arranged instead of the board. In some cases the end finish is obtained solely by means of the metal sheet cap which is extended downwardly over the openings formed by the corrugated metal sheet an insert of insulating material being provided. The end finish of the roof shown at the board 29 may also be arranged at the roof base instead of the end finish shown.

The gap between the panels 18 at the roof apex is covered in the same way as the openings between the slabs by using strips or ribs 18', as described above.

It is advantageous to arrange the roof as prefabricated slabs, as described above, but the invention is not limited to this embodiment; it can also be used for roofs of the type wherein a concrete slab moulded in situ is arranged on the beams 11. In this case the Z-sections 16 as well as the slabs 18 must, of course, be mounted at the site and the same benefits are, of course, obtained also in this case regarding the use of soft cheap insulation material as in case of prefabricated slabs, but the working time on the roof will be essentially longer which is an obvious disadvantage. FIG. 5 discloses how the connector, comprising the two halves 101 and 102, connects the two portions 116a and 116b of the spacer. The connector, preferably made of a plastics material, is dimensioned to have a sufficient supporting ability so as to transmit compressive strain from the upper part 116a of the spacer to the lower part 116b thereof. The embodiment of the connector according to FIGS. 5 and 6 allows a simple attachment to the upper and lower parts of the spacer by providing one half 101 of the connector with a dovetail-type projection 103 intended to fit into a recess 104 in the other half 102 of the connector, the recess receiving substantially completely the dovetail-type projection 103 of the first half 101. To make possible to perform the connection by means of the connector according to FIGS. 5 and 6 the ends of the spacer must be folded in such a way that they sealingly engage the projection 103 of dovetail-type and the wall of the recess 104, respectively. The spacer 116 can be prefabricated and delivered with a mounted connector, but it is also possible to manufacture and deliver the connector in pieces to be joined and mounted at the building site. In the latter embodiment the edge portions of the side surfaces of the two halves of the connector, facing each other are preferably bevelled to facilitate the insertion of the two halves to the position shown in FIGS. 5 and 6a. Accordingly, the two halves 101 and 102 of the connector are kept together by frictional forces, which means that the mounting will be easy and can be performed quickly. The connector is able to transmit compressive strains as well as tensile strains between the two parts 116a and 116b of the spacer, and at the same time a good heat insulation is obtained between these parts.

FIG. 7 discloses another embodiment of the connector, the two halves 101' and 102' of which have a perpendicular projection 103' and a rectangular recess 104', respectively. However, this embodiment of the connector requires a uniting force which is obtained by conventional fasteners 105 such as rivets or screws, which are placed at both sides of the extension 103' and the recess 104', respectively, but also in this case the tensile and compressive strains, respectively, should be transferred from the upper part 116a of the connector to the lower part 116b thereof over folded portions A, B, respectively, which means that the fasteners have to be dimensioned for low strains only.

Claims

1. Roof comprising a supporting deck (14) provided with a heat insulation (21) and a roof finish (23), c h a r a c t e r i z e d in that the supporting deck (14) comprises a prefabricated element and supports a self-supporting panel (18) by means of rigid metal sheet sections (16) forming spacers between the supporting element (14) and the panel (18), and that the space beneath the panel (18) is filled with a soft heat insulating material (21).

2. Roof according to claim 1, c h a r a c t e r i z e d in that the prefabricated supporting element (14) together with the metal sheet section (16), the insulating material (21) and the panel (18) are made as a self-supporting roof slab (13).

3. Roof according to claim 2, c h a r a c t e r i z e d in that the prefabricated element comprises a corrugated metal sheet (14).

4. Roof according to claim 2 or 3, c h a r a c - t e r i z e d in that the prefabricated element (14) extends beyond the metal sheet sections (16) and beyond the panel (18) at least at one of the outer edges of the roof slab (13).

5. Roof according to claim 4, c h a r a c t e r - i z e d in that the roof slabs (13) are attached to the supporting construction (11) of the roof at the projecting edge portions of the prefabricated element (14).

6. Roof according to claim 5, c h a r a c t e r i z e d in that spaces formed above the projecting edge portions of the prefabricated elements (14) between adjacent roof slabs (13) are filled with insulating material (21') and covering ribs (18') of the same material as the slabs.

7. Roof according to claim 6, c h a r a c t e r i z e d in that the metal sheet sections (16) project from the edges of the panel (18) to form shoulders supporting the rib (18') at said edges.

8. Roof according to any of the preceding claims c h a r a c t e r i z e d in that a vapour barrier (15) made of plastics film is arranged between the supporting deck (14) and the heat insulation (21).

9. Roof according to any of the preceding claims c h a r a c t e r i z e d in that the metal sheet sections (16) at a base of the roof, joining a crown of a wall, have a height increasing towards the crown of the wall over a portion (13') adjacent the crown of the wall in order that the portion of the panel (18) supported by said portion shall form a gutter together with the rest of the panel.

10. Roof according to claim l. c h a r a c t e ri z e d in that the spacers (116) supporting the panels (118) are made of two parts (116a, 116b) and an intermediate connector (101, 102), connecting the parts, of a material having a low heat conductivity.

11. Roof according to claim 10, ch a r a c t e ri z e d in that the connector comprises two halves (101, 102) arranged to receive therebetween oppositely directed end portions of the two parts (116a, 116b) of the spacer and to retain such portions.

12. Roof according to claim ll. c h a r a c t e ri z e d in that the two halves (101, 102) of the connector have a projection (103) and a recess (104), respectively, the two oppositely directed edge portions of the parts (116a, 116b) being bent to cooperate between the extension and the recess, respectively.

13. Roof according to claim 12, c h a r a c t e r i z e d in that the projection (103) and the recess (104) are of dovetail-type.

14. Roof according to claim 12, c h a r a c t e ri z e d in that the projection (103') and the recess (104') are of rectangular shape.